Characteristics of Paleoseismic Activity Along the Tianqiaogou-Huangyangchuan Fault on the Eastern Section of the Qilian Mountains

作     者：Zheng Wenjun Yuan Daoyang He Wengui 

作者机构：Lanzhou Base of Earthquake Prediction Institute China Earthquake Administration Lanzhou 730000 China Lanzhou Institute of Seismology China Earthquake Administration Lanzhou 730000 China 

出 版 物：《Earthquake Research in China》 (中国地震研究（英文版）)

年 卷 期：2005年第19卷第2期

页      面：139-151页

学科分类：070801[理学-固体地球物理学] 07[理学] 0708[理学-地球物理学] 

基　　金：TheresearchwassupportedbytheJointEarthquakeScienceFoundation(102055)and(604018).TheLanzhouBaseofEarthquakePredictionInstitute ChinaEarthquakeAdministration contributionNo.LC2003050 

主　　题：Active fault Trench Geological logging Paleoseismic event Gulang Gansu 

摘      要：The Tianqiaogou-Huangyangchuan fault lies east of the main peak, Lenglongling Mount, in the east part of the Qilian Mountains and is one of the major active faults on the eastern section of the Qilian Mountains. The fault is separated into two segments at Guanjiatai village, the eastern and western segments, and has undergone obvious movement since the Holocene. Six trenches were excavated to study the pa!eoseismic activity along the fault. Integrated and comparative analysis of sediments in the trenches reveals 7 paleoseismic events and a historic earthquake on the fault since the Holocene. Their ages are： event Ⅰ is （10743 ± 343 ）a BP,event Ⅱ （9038 ± 39）a BP, event Ⅲ （7050 ± 577）a BP, event Ⅳ （4847 ± 185）a BP, event Ⅴ（3562 ± 190）a BP, event Ⅵ （2476 ±194） a BP, and event Ⅶ（1505 ± 253）, respectively, and event Ⅷ is the 1927 Gulang Ms8. 0 earthquake. It indicates that the fault might have contributed to the 1927 Gulang Ms8.0 earthquake. The temporal and spatial distribution of the paleoseismic events is relatively uniform and is characterized approximately by a quasiperiodic recurrence.